1. Field of Invention
The invention relates to keyboards and more particularly to a computer keyboard having uniformly, sufficiently illuminated key members.
2. Description of Related Art
Typically, a keyboard comprises a plurality of key members which display symbols, such as alphanumeric keys, on their top surfaces. A problem with conventional keyboards is that it is often difficult to discern the symbol appearing on top of the key member under poor lighting conditions. This forces a keyboard operator to strain his or her eyes to operate the keys under low light conditions. This has become a much greater problem in present day society as keyboards have become necessary for everyday use.
Moreover, the advent of laptops has resulted in the use of keyboards at places where they were not previously operated. It is often that these places provide limited light making it difficult for keyboard operators to easily operate the keyboard.
A number of prior patents about illuminated keyboard are disclosed. For example, Taiwanese Utility Model Patent No. M324,816 discloses a keyboard with backlight arrangement. However, in practice it is found that keys distal the LED (light-emitting diode) based backlight arrangement are not sufficiently illuminated. That is, keys are not illuminated uniformly.
Also, U.S. Pat. No. 7,608,792 discloses a “Membrane keyboard/keypad with arrangement for uniformly lighting keys from background”. Thus, continuing improvements of illuminated keyboard are constantly sought.